Bandwidth reduction in CW fiber Raman lasers

The oscillation linewidth of CW fiber Raman lasers has been reduced from typical uncontrolled values of 200 GHz (approximately 0.2 nm for 528 nm radiation) to 9 GHz by employing prisms, gratings, and etalons in various resonator configurations. Further reduction is limited by four-wave mixing and stimulated Brillouin scattering. Although four-wave mixing limits bandwidth reduction, the results demonstrate the use of this nonlinear process for intensity stabilization.